metrics: support multi-k8s in grafana dashboards (#4671)

[ti-chi-bot]

This is an automated cherry-pick of #4671

Signed-off-by: just1900 [email protected]

What problem does this PR solve?

Issue Number: close #4673

K8s community and organizations are increasingly deploying multiple Kubernetes clusters to improve availability, isolation and scalability. Since TiDB Operator have support deploying tidb across-kubernetes, this PR will address the multi-k8s issue without affecting existing single-cluster use case.

What is changed and how it works?

What's Changed:

• add a k8s_cluster label in all expr
• add k8s_cluster variable in Grafana templating

How it works:

• For users with single-k8s, nothing need to be changed, just use it as before.
• For users with multi-k8s:
  • first add kubernetes label to identify k8s cluster in your prometheus' external_labels.
  • set field "hide" to '0' to show variables in grafana via sed -i s/"hide": 2/"hide": 0/g <path/to/dashboard.json>
  • load it to grafana

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Code changes

• Has configuration change
• Has HTTP API interfaces change (Don't forget to add the declarative for API)
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• tidb metrics: Support multi k8s in grafana dashboards pingcap/tidb#32546
• tikv metrics: support multi k8s in grafana dashboards tikv#12008
• PR to update pingcap/docs/pingcap/docs-cn:
• PR to update pingcap/tiup:
• Need to cherry-pick to the release branch

Release note

metrics: support multi-k8s in grafana dashboards

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• nolouch
• rleungx

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[nolouch]

/merge

[ti-chi-bot]

@nolouch: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: ff7c27a

[codecov]

Codecov Report

Merging #4717 (ff7c27a) into release-5.4 (749c931) will decrease coverage by 0.03%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           release-5.4    #4717      +/-   ##
===============================================
- Coverage        74.71%   74.68%   -0.04%     
===============================================
  Files              265      265              
  Lines            27963    27963              
===============================================
- Hits             20893    20884       -9     
- Misses            5210     5213       +3     
- Partials          1860     1866       +6     

Flag	Coverage Δ
unittests	74.68% <ø> (-0.04%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
server/tso/local_allocator.go	64.86% <0.00%> (-13.52%)	⬇️
server/schedule/region_scatterer.go	78.99% <0.00%> (-4.21%)	⬇️
server/schedule/labeler/labeler.go	79.45% <0.00%> (-2.74%)	⬇️
server/member/member.go	65.24% <0.00%> (-1.61%)	⬇️
pkg/btree/btree.go	85.78% <0.00%> (-0.97%)	⬇️
server/core/storage.go	69.31% <0.00%> (-0.76%)	⬇️
server/server.go	72.00% <0.00%> (-0.30%)	⬇️
server/cluster/cluster.go	82.62% <0.00%> (-0.24%)	⬇️
server/grpc_service.go	51.59% <0.00%> (-0.20%)	⬇️
client/client.go	72.61% <0.00%> (-0.11%)	⬇️
... and 7 more

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